The purpose of this program, which is entering its 36th year, is to train postdoctoral fellows in research on a variety of types of plasticity that influence the nervous system, including neuronal development, changes in motivational state, selective attention, learning, and disease. The neurobiological bases of these processes will be studied, emphasizing analyses of synaptic specification, control of gene expression, structure of the cytoskeleton, synaptic plasticity, organization of neural circuits, structure and gating properties of membrane conductance channels, neurochemistry of synaptic transmission, axonal transport and neuronal regeneration. A multidisciplinary approach will be taught that in most cases can be directed towards an analysis of these problems at the molecular level. Training will be offered in a variety of disciplines, including membrane biophysics, anatomy and cell biology, behavior, development, electrophysiology, molecular biology, neurochemistry, pharmacology and physiology, and brain imaging. Each fellow will be encouraged to become familiar with a variety of neurobiological disciplines in order to instill a problem-oriented, as opposed to a technique-oriented, approach to science. Trainees will be encouraged to work on problems of fundamental importance to basic neural science, with the long term goal that the resulting knowledge will someday be of importance in the prevention and treatment of neurological and psychiatric diseases. The training faculty are members of the Center for Neurobiology or (in one case) the Department of Psychiatry of Columbia University. The training program is built primarily around the research and training activities and the facilities of the Center. The 29 members of the training faculty have a wide diversity of expertise, and various members hold joint appointments in 7 different basic science and clinical departments of the University. There will be extensive active collaboration between members of the training faculty in their research and in the training of pre- and postdoctoral students. Trainees will participate in graduate courses and seminars, but their primary training experience will come in an intensive 3-4 year research program in the laboratory of one of the training faculty. The program will be broadly advertised at the national level, and a vigorous effort will be made to recruit women and members of underrepresented minority groups. Funds are requested for four postdoctoral trainees per year.